The invention is based on an electromagnetic rotating actuator as defined hereinafter. An electromagnetic rotating actuator has already been proposed (German Patent Application P 39 26 912.4), in which a roller bearing at a poorly accessible location is axially held by means of a spring washer and an angle washer that locks into place in a detent, so that the roller bearing remains fixed during assembly and operation of the rotating actuator. However, this fixation of the roller bearing is neither suitable for machine assembly in mass production nor is it economical, nor is it suitable for use with a housing that extends across the entire servomotor.